I'd use a metal paint scraper first to make sure you've got rid of all the bubbled paint and then go over it with scotch brite, the red stuff if you have it. Clean it really well and then get some touch up paint that's close to the color of your Jeep and spray it. Newer spray doesn't need primer or anything else. Just make sure it has plenty of time to dry before you cover it up, it can take several days to harden. If you don't care what it looks like brush on rustoleum goes on think and will protect it better but it'll show.